The field of the invention relates to gas distribution apparatus and particularly to apparatus for distributing breathable gas from a very high pressure source to individual respirators at suitable pressure over atmospheric pressure for their comfortable use.
In industrial and research environments it is at times necessary for personnel to enter contaminated areas in order to clean them, change filtering units and the like. Such areas may be contaminated by chemicals, biological agents and radioactive material. When personnel must enter such areas they wear suitable protective clothing and although they are only in the area for a short time because of the great dangers inherent in exposures in such areas, they are in the areas for a sufficient length of time that they require breathing apparatus. In some cases individuals carry apparatus such as air tanks on their backs. However, manually carried tanks are heavy and cumbersome, will be contaminated in use, cannot be reused, and must be carefully treated as waste. In addition, they may interfere with the protective clothing necessarily worn by the individuals going into the contaminated areas. If possible, it is usually desirable that air from a source outside the contaminated area be ducted through hoses into the room, vault or other contaminated area needing clean up. Typical breathing apparatus comprises individual full-face masks well known to those skilled in the art. Such face masks connect to a source of air or other breathable gas such as a mixture of oxygen and nitrogen through individual conduits or hoses which enter a vault or room through sealable wall ports. After their use, at least in radioactive environments, the hoses which carry the air or gas as well as the face masks are burned or otherwise suitably destroyed. They almost never can be removed from radioactively contaminated areas and reused.
With prior art devices, it has been very difficult to safely control air pressure at each individual face mask and if pressure to a mask is inadequate an individual wearing it may rip it off and breath the contaminated air. In the worst case death could result. At best some chemical or radioactive material is absorbed and medical treatment of the individual is required. If pressure to a face mask is too high it is extremely uncomfortable for an individual to continue to wear the mask and work in the contaminated area, usually necessarily for several hours. Using typical prior art devices, if air is cut off to one of a plurality of individual face masks, such as from a kink in the hose to that mask, pressure increases to other face masks connected to the same air supply. This too is highly undesirable and extreme discomfort from excessive pressure results to the wearers of the other face masks.
One object of the present invention is to provide a regulated supply of air or breathable gas to individuals working in contaminated areas.
Another object of the present invention is to provide a series of air pressure relief valves and alarms so that air or breathable gas pressure does not increase above a desirable level at face masks of personnel working in contaminated areas, and if it is about to, they are warned.
Another object of the present invention is to distribute air or other breathable gas to a plurality of individuals working in a contaminated area in a manner that pressure at each face mask is independent of the pressure at all others so that in case of accident or crimping of a hose, pressures do not rise above a desirable amount in the remaining masks.
One advantage of the instant invention is that at least one of a series of alarms initiates if air pressure exceeds a desired amount.
Another advantage of the instant invention is that gauges are disposed at critical pressure reduction parts of the apparatus thereby providing for monitoring outside the contaminated area being serviced.
A third advantage of the instant invention is that a plurality of audible alarms are provided if gas pressure exceeds a limit amount at any one of several stages of pressure reduction.
Another advantage of the instant invention is that a preferred embodiment thereof is portable and may be readily carried about on a push cart and can be easily taken to a contaminated area requiring immediate attention.